New Haven, CT—As pharmacists well know, insulin prices have tripled in the United States over the past decade, with out-of-pocket costs per prescription doubling.

A new study published in JAMA Internal Medicine said the cost burdens can have a detrimental effect on medication adherence. Yale School of Medicine–led researchers report that in a small survey of patients at an urban diabetes center, one out of four said they held back on using their prescribed insulin because of cost. The result was poor glycemic control.

“Insulin is lifesaving for people with diabetes and is included on the Model List of Essential Medicines formulated by the World Health Organization,” study authors emphasized. “This means it should be available at all times at a price the individual and the community can afford.”

The survey was administered to diabetes patients who had been prescribed insulin within the past 6 months and who had an outpatient visit at the Yale Diabetes Center between June and August 2017.

Participants were asked the following questions: Did you, because of cost
• Use less insulin than prescribed
• Try to stretch out your insulin
• Take smaller doses of insulin than prescribed
• Stop using insulin
• Not fill an insulin prescription
• Not start insulin

The study notes that of 199 patients with type 1 or type 2 diabetes who were prescribed insulin and who completed the survey, 25.5% admitted cost-related underuse of insulin. Complicating the situation, according to the researchers, is that more than a third of the patients with cost-related underuse did not discuss the issue with their physicians.

Participants were 52% women and 54% white. Most, 56.2%, had type 2 diabetes. Those who reported cost-related issues with insulin were more likely to report lower incomes.

With 60.8% of those patients saying they discussed the affordability issue with their clinician, 29.4% changed prescriptions due to cost. Patients reporting cost-related underuse were more likely to have poor glycemic control in the multivariable analysis (22 [43.1%] versus 41 [28.1%]; odds ratio = 2.96; 95% CI, 1.14-8.16; P = .03).

Despite the limitations of the single-center study, the study team suggested the results highlight an urgent need to address the affordability of insulin, adding, “At minimum, individual clinicians should screen all patients for cost issues to help them address these challenges.”

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